Teaching aid for displaying line-plane relation and preliminarily measuring angle

Abstract

The invention discloses a teaching aid for line-plane relation display and angle preliminary measurement, which comprises a measurement turntable with scales, and is characterized in that one side of the measurement turntable is rotatably connected with a fixed seat, and the fixed seat is used for being clamped on a to-be-measured edge of a to-be-measured model; the other side of the measuring turntable is rotationally connected with a movable adaptive frame, and the movable adaptive frame is used for being aligned with the other to-be-measured edge of the to-be-measured model; an indicating rod is connected to the movable adapting frame in a sliding mode and slides close to or away from the measuring rotary disc along the movable adapting frame, and elastic connecting ropes are arranged at the two ends of the indicating rod and used for determining three vertexes of an angle according to the real scene requirement. The teaching aid for displaying the line-plane relation and preliminarily measuring the angle solves the problems that an existing protractor cannot visually display the relation between different-plane straight lines, the different-plane straight line included angle calculation process is difficult, students are difficult to understand, and the learning progress and learning efficiency of the students are affected.

Description

Technical Field

[0001] The invention relates to the technical field of measuring teaching aids, and in particular to a teaching aid for line-surface relationship display and preliminary angle measurement. Background Art

[0002] A protractor is a drawing tool that can be used to draw the desired angle or measure the angle between two straight lines. In primary school, students learned about angles and used a protractor to measure the size of angles. In junior high school, they further learned the concept of angles and the calculation of angles. For situations where the actual measurement can only be made by extending, auxiliary lines are needed for auxiliary measurement, and the results cannot be obtained directly. In addition, the understanding and calculation of angles, after the transition from plane geometry to solid geometry, the calculation of the angle between two non-coplanar straight lines appeared. How to find the required angle is a key and difficult point that needs to be solved in teaching. The scope of use of ordinary protractors is narrow and can only be applied to the understanding of angles in primary school. Even after the protractor is improved in junior high school, the measurement of non-intersecting angles can be solved, but it is not helpful for the learning of preliminary knowledge of solid geometry in high school, and the thinking and solution of borrowing one's own spatial imagination. For example, for the relevant content of the line-plane relationship unit in the preliminary solid geometry of high school mathematics (line-line relationship, line-plane relationship, plane-plane relationship, etc.), especially the calculation of "angle formed by non-coplanar straight lines", one of the key points of national mathematics knowledge assessment, the original protractors and improved instruments are no longer capable of helping students to intuitively see the position of the angle, and how to use the principle of equivalent substitution, use existing conditions, and use the cosine theorem to calculate the required value. How to enable students to calculate the degree of different angles through analytical methods and intuitively demonstrate the internal logic of the generation of various angles. In particular, helping students to construct the formation process of disintegration in their minds is a problem that needs to be solved through teaching aids.

[0003] Therefore, it is necessary to develop a teaching aid for displaying line-surface relationships and preliminary angle measurements to address the above defects. Summary of the invention

[0004] The purpose of the present invention is to provide a teaching aid for displaying the relationship between lines and planes and for preliminary angle measurement, which can solve the problem that existing goniometers cannot intuitively display the relationship between skew lines, resulting in difficulty in calculating the angle between skew lines, difficulty for students to understand, and impact on students' learning progress and efficiency.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] The present invention discloses a teaching aid for demonstrating line-surface relationship and preliminary angle measurement, comprising a measuring turntable provided with a scale, wherein one side of the measuring turntable is rotatably connected to a fixing seat, and the fixing seat is used to be clamped on a side to be measured of a model to be measured; the other side of the measuring turntable is rotatably connected to a movable adapter frame, and the movable adapter frame is used to align with another side to be measured of the model to be measured; the movable adapter frame is slidably connected to an indicating rod, and the indicating rod slides along the movable adapter frame to approach or move away from the measuring turntable.

[0007] Furthermore, the movable adapter frame includes a first rod body rotatably connected to the measuring turntable, two second rod bodies are rotatably connected to the first rod body, and the two second rod bodies are arranged in parallel; a third rod body is rotatably connected between the two second rod bodies, and the third rod body is parallel to the first rod body.

[0008] Furthermore, the fixing seat includes a fixing rod rotatably connected to the measuring turntable, and a plurality of elastic clips are arranged at intervals on the fixing rod. The elastic clips are provided with mounting bayonet holes, and the mounting bayonet holes are arranged in a direction away from the measuring turntable for being clamped on a side to be measured of the model to be measured.

[0009] Furthermore, the indicating rod comprises a fourth rod body parallel to the first rod body, the fourth rod body is connected to two sliding blocks, the sliding blocks are slidably mounted on the second rod body and correspond one-to-one with the second rod body.

[0010] Furthermore, the measuring turntable includes a first disk body and a second disk body, the first disk body and the second disk body are both semicircular structures, the first disk body and the second disk body are coaxially arranged, the first disk body is against the first rod body, and the second disk body is arranged on the side of the first disk body away from the first rod body; the first disk body and the second disk body are both rotatably connected with a rotating shaft, one end of the rotating shaft is provided with a locking protrusion, and the other end passes through the first rod body, the first disk body and the second disk body in sequence and is connected to the fixed rod.

[0011] Furthermore, the first rod and the two second rods, the third rod and the two second rods, and the fourth rod and the two sliding blocks are rotatably connected via fasteners.

[0012] Furthermore, the fasteners connected between the fourth rod and the two sliding blocks are detachably connected with elastic connecting ropes, and the two elastic connecting ropes cooperate with the fourth rod to determine the three vertices of the angle.

[0013] Furthermore, the first rod body, the third rod body and the fourth rod body are each provided with a plurality of mounting holes at equal intervals, and the plurality of mounting holes are used for the passage of the fasteners; the two second rod bodies are each provided with a plurality of fixing holes at equal intervals, and the sliding block is provided with fastening holes, and the plurality of fixing holes and the fastening holes are both used for fixedly connecting the fasteners.

[0014] Furthermore, the rotating shaft is sleeved with a first locking member and a second locking member, the first locking member is arranged between the locking cam and the first rod body, and is used to fix the position of the first rod body; the second locking member is arranged between the second disk body and the fixing rod, and is used to fix the position of the second disk body; the first locking member and the second locking member are both threadedly connected to the rotating shaft.

[0015] Furthermore, the fixing rod is a long strip structure, and a plurality of the elastic buckles are arranged at intervals along the length direction of the fixing rod.

[0016] Compared with the prior art, the beneficial technical effects of the present invention are:

[0017] The present invention discloses a teaching aid for displaying the relationship between lines and planes and for preliminary measurement of angles. The teaching aid is based on training students to improve their spatial imagination. Through the adaptation setting of a movable adapter frame and a fixed seat that are relatively rotatable, the two skew lines in the model to be tested can be aligned respectively, so as to more intuitively display the relationship between the skew lines. Through the indication rod that is slidably arranged, the changing process of the skew lines after being moved to the same plane can be intuitively displayed after alignment, so as to improve the dynamic ability of the display and enable students to understand relevant knowledge more quickly. Through the setting of a measuring turntable, the angle between the skew lines can be directly measured, and comprehensive learning can be carried out by comparing the calculation results, so that students can better combine theory with practice, increase their ability to understand spatial three-dimensional structures, and effectively improve learning efficiency. The key point is that the formation process of the relationship between lines and planes can be intuitively displayed, so as to form a basis for spatial imagination. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described below in conjunction with the accompanying drawings.

[0019] Figure 1 A schematic diagram of the three-dimensional structure of the teaching aid for displaying line-surface relationships and preliminary angle measurement of the present invention;

[0020] Figure 2 A schematic diagram of the side view structure of the teaching aid for line-surface relationship display and preliminary angle measurement of the present invention;

[0021] Figure 3 For along Figure 2 The cross-sectional structure diagram along the AA line;

[0022] Figure 4 for Figure 3 A schematic diagram of the enlarged structure at B in the middle;

[0023] Figure 5 A schematic side view of another embodiment of the teaching aid for line-surface relationship display and preliminary angle measurement of the present invention;

[0024] Figure 6 It is a schematic cross-sectional structural diagram of a fixing rod portion in another embodiment of the present invention;

[0025] Figure 7 Picture 1 is a picture of the actual use of the present invention;

[0026] Figure 8 This is the second picture when the present invention is actually used.

[0027] Explanation of the accompanying drawings: 1. Measuring turntable; 2. Fixed seat; 3. Movable adapter frame; 4. Indicator rod; 5. Elastic connecting rope; 11. First disk body; 12. Second disk body; 13. Rotating shaft; 14. Boss; 15. First locking member; 16. Second locking member; 21. Fixed rod; 22. Elastic buckle; 31. First rod body; 32. Second rod body; 33. Third rod body; 41. Fourth rod body; 42. Sliding block; 43. Fastener; 131. Guide block; 211. Slide rail; 221. Mounting bayonet; 321. Fixing hole. DETAILED DESCRIPTION

[0028] The core of the present invention is to provide a teaching aid for displaying the relationship between lines and planes and for preliminary angle measurement, which can solve the problem that existing goniometers cannot intuitively display the relationship between skew lines, resulting in difficulty in calculating the angle between skew lines, difficulty for students to understand, and impact on students' learning progress and efficiency.

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0031] Please also read Figures 1 to 5Now, a specific implementation of a teaching aid for displaying line-plane relationship and preliminary angle measurement provided by the present invention is described. The teaching aid for displaying line-plane relationship and preliminary angle measurement includes a measuring turntable 1 provided with a scale, one side of the measuring turntable 1 is rotatably connected to a fixing seat 2, and the fixing seat 2 is used to be clamped on a side to be measured of the model to be measured; the other side of the measuring turntable 1 is rotatably connected to a movable adapter frame 3, and the movable adapter frame 3 is used to align with another side to be measured of the model to be measured; the movable adapter frame 3 is slidably connected to an indicator rod 4, and the indicator rod 4 slides along the movable adapter frame 3 to approach or move away from the measuring turntable 1.

[0032] For illustration purposes, see Figure 1 , take any point in the space as the origin, take the setting direction of the first rod 31 in the movable adapter frame 3 relative to the fixed seat 2 as the Z axis, take the setting direction of the fourth rod 41 in the indicating rod 4 as the Y axis, and take the straight line direction perpendicular to both the Y axis and the Z axis as the X axis to establish a rectangular coordinate system, wherein the XY plane is a horizontal plane, the direction indicated on the horizontal plane is the horizontal direction, and the direction indicated by the Z axis is the vertical direction.

[0033] When in use, fix the fixed seat 2 on a measuring edge of the model to be tested; rotate the movable adapter frame 3 to align one side of the movable adapter frame 3 away from the fixed seat 2 with another measuring edge of the model to be tested; rotate the measuring turntable 1 to measure the angle between the side of the movable adapter frame 3 close to the fixed seat 2 and the fixed seat 2; move the indicator rod 4 to more intuitively show students the relationship between the straight lines at both ends of the movable adapter frame 3, and the positional relationship after the skew lines are moved to the same plane, etc.; compare the measured angle with the theoretically calculated structure, combine theory with practice, and better master relevant knowledge.

[0034] Compared with the prior art, this teaching aid for line-plane relationship display and preliminary angle measurement can be aligned with two skew lines in the model to be tested respectively through the adaptation setting of the movable adapter frame 3 and the fixed seat 2 which are relatively rotated, so as to more intuitively display the relationship between the skew lines; through the indicator rod 4 which is slidingly arranged, after alignment, the change process of the skew lines after moving to the same plane can be intuitively displayed, so as to improve the dynamic ability of the display and enable students to understand the relevant knowledge more quickly; through the setting of the measuring turntable 1, the angle between the skew lines can be directly measured, and comprehensive learning can be carried out by comparing with the calculation results, so that students can better combine theory with practice, increase their understanding of spatial three-dimensional structure, and effectively improve learning efficiency.

[0035] In a specific embodiment of the present invention, the movable adapter frame 3 includes a first rod body 31 rotatably connected to the measuring turntable 1, and two second rod bodies 32 are rotatably connected to the first rod body 31, and the two second rod bodies 32 are arranged parallel to each other; a third rod body 33 is rotatably connected between the two second rod bodies 32, and the third rod body 33 is parallel to the first rod body 31.

[0036] In this embodiment, the connection points between the first rod 31 and the two second rods 32 , and the connection points between the third rod 33 and the two second rods 32 , are connected in sequence to form a parallelogram.

[0037] In a specific embodiment of the present invention, the fixing base 2 includes a fixing rod 21 rotatably connected to the measuring turntable 1, and a plurality of elastic clips 22 are arranged at intervals on the fixing rod 21. The elastic clips 22 are provided with mounting sockets 221, and the mounting sockets 221 are arranged in a direction away from the measuring turntable 1, and are used to be clamped on a side to be measured of the model to be measured.

[0038] In this embodiment, the fixing rod 21 is a long strip structure, and a plurality of elastic buckles 22 are arranged at intervals along the length direction of the fixing rod 21; the elastic buckles 22 are fixed to the fixing rod 21. Here, as long as the above-mentioned elastic buckles 22 can achieve the relevant performance and function, they are within the protection scope of this application.

[0039] In a specific embodiment of the present invention, the indicator rod 4 includes a fourth rod 41 parallel to the first rod 31 , and the fourth rod 41 is connected to two sliding blocks 42 , which are slidably mounted on the second rod 32 and correspond to the second rod 32 one by one.

[0040] In this embodiment, the sliding block 42 is a C-shaped structure, the second rod 32 is arranged through the sliding block 42, and the hole formed in the middle of the C-shaped structure of the sliding block 42 is adapted to the structure of the second rod 32. The first rod 31 and the two second rods 32, the third rod 33 and the two second rods 32, and the fourth rod 41 and the two sliding blocks 42 are all rotatably connected by fasteners 43.

[0041] In a specific embodiment of the present invention, the fastener 43 connected between the fourth rod 41 and the two sliding blocks 42 can be detachably connected with an elastic connecting rope 5, and the two elastic connecting ropes 5 cooperate with the fourth rod 41 to determine the three vertices of the angle. When the equivalent replacement of the angle is displayed in real scene, the two elastic connecting ropes 5 can adjust the length according to the size of the solid geometric body, and then form a triangle with the fourth rod 41. Exemplarily, when used in the measurement of the angle between non-coplanar straight lines in a triangular pyramid, the fourth rod 41 is moved to the midpoint position of the other two sides of the triangle where the side to be measured is located, and the ends of the two elastic connecting ropes 5 away from the fastener 43 are fixed to the midpoint position of the third side connected to the fourth rod 41. At this time, the two elastic connecting ropes 5 and the fourth rod 41 form a triangle, and the angle between the fourth rod 41 and the corresponding elastic connecting rope 5 can be determined as the angle between non-coplanar straight lines according to the parallel relationship. This step can more intuitively show the analysis and solution logic and process of the angle between non-coplanar straight lines.

[0042] In this embodiment, the fastener 43 may be a bolt; the first rod 31, the third rod 33 and the fourth rod 41 are provided with a plurality of mounting holes at equal intervals, and the plurality of mounting holes are used for the passage of the fastener 43; the two second rods 32 are provided with a plurality of fixing holes 321 at equal intervals, and the sliding block 42 is provided with fastening holes, and the plurality of fixing holes 321 and the fastening holes may be threaded holes for fixing and connecting the fastener 43. The fastener 43 on the sliding block 42 penetrates the fourth rod 41 and is threadedly connected with the fastening hole on the sliding block 42, and the fourth rod 41 can be flexibly moved up and down along the second rod 32 at this time; after the fastener 43 is continuously rotated so that the fastener 43 completely penetrates the sliding block 42 and abuts against the second rod 32, the sliding block 42 can be fixed, and then the fourth rod 41 can be fixed. The structure is more flexible in operation, and the fourth rod 41 can be loosened and fixed as needed. In addition, the spacing between the four connection points in the movable adapter frame 3 can also be adaptively adjusted according to the size of the model, so that the scope of application is wider and the flexibility of use is better.

[0043] In a specific embodiment of the present invention, the measuring turntable 1 includes a first disk body 11 and a second disk body 12, both of which are semicircular structures, the first disk body 11 and the second disk body 12 are coaxially arranged, the first disk body 11 is against the first rod body 31, and the second disk body 12 is arranged on the side of the first disk body 11 away from the first rod body 31; the first disk body 11 and the second disk body 12 are both rotatably connected with a rotating shaft 13, one end of the rotating shaft 13 is provided with a locking protrusion 14, and the other end passes through the first rod body 31, the first disk body 11 and the second disk body 12 in sequence and is connected to the fixed rod 21.

[0044] In this embodiment, the first locking member 15 and the second locking member 16 are sleeved on the rotating shaft 13. The first locking member 15 is arranged between the locking protrusion 14 and the first rod body 31, and is used to fix the position of the first rod body 31; the second locking member 16 is arranged between the second disk body 12 and the fixing rod 21, and is used to fix the position of the second disk body 12; the first locking member 15 and the second locking member 16 are both threadedly connected to the rotating shaft 13, and the first locking member 15 and the second locking member 16 can both be nuts, and the rotating shaft 13 is provided with threads.

[0045] In this embodiment, the fixing rod 21 is fixedly connected to the bottom of the rotating shaft 13. By rotating and adjusting the positions of the first locking member 15 and the second locking member 16, the fixing rod 21, the first disk body 11, the second disk body 12 and the first rod body 31 can be fixedly limited. Through the setting of the elastic buckle 22, the fixing rod 21 and the rotating shaft 13 can rotate freely along the circumference of the edge to be measured. Here, as long as the related performance functions of the first locking member 15 and the second locking member 16 can be achieved, they are all within the scope of protection of this application document.

[0046] Compared with the prior art, this kind of teaching aid for displaying the relationship between lines and planes and for preliminary angle measurement can intuitively demonstrate the relationship between lines, lines and planes, planes and planes, etc. Students in ordinary high schools generally have difficulties in learning the preliminary knowledge of high school solid geometry. In the current teaching process, the main problem is that solid geometric bodies are difficult to quickly construct in the brain, difficult to move and stand up. With the help of this teaching aid, the process of intuitive demonstration of knowledge can be implanted in the students' brains, helping them to quickly establish spatial concepts, stimulate interest, and improve their abilities. By using the elastic connecting rope 5, a triangle is constructed, and the cosine theorem is used to solve the problem of obtaining the calculated value of the angle using known conditions.

[0047] Please also read Figures 1 to 6 In a specific embodiment of the present invention, a slide rail 211 is provided on the fixed rod 21, a slide groove is provided on the slide rail 211, and a guide block 131 is provided at the bottom of the rotating shaft 13 and is slidably mounted on the slide rail 211; the upper surface of the fixed rod 21 is arc-shaped, the slide rail 211 is an arc-shaped track coaxial with the fixed rod 21, the slide rail 211 is arranged along the circumference of the fixed rod 21, and the guide block 131 is provided with an arc-shaped guide hole adapted to the slide rail 211. With this structural setting, after the elastic buckle 22 is fixed on the edge to be measured, the measuring turntable 1 and the movable adapter frame 3 above can rotate freely and more flexibly along the fixed rod 21, better match the position of the other edge, and be more flexible to use.

[0048] In this embodiment, the first plate 11 is fixedly connected to the second plate 12, and the second plate 12 is fixedly connected to the fixing rod 21, and the fixing rod 21 is arranged flush with the zero scale line. In this way, it is more convenient to measure the preliminary angle value when using it, and it is more convenient to use.

[0049] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0050] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A teaching aid for demonstrating line-surface relationships and preliminary angle measurement, characterized in that: The invention comprises a measuring turntable (1) provided with a scale, wherein one side of the measuring turntable (1) is rotatably connected to a fixing seat (2), and the fixing seat (2) is used to be clamped on a side to be measured of the model to be measured; the other side of the measuring turntable (1) is rotatably connected to a movable adapter frame (3), and the movable adapter frame (3) is used to align with the other side to be measured of the model to be measured; and the movable adapter frame (3) is slidably connected to an indicating rod (4), and the indicating rod (4) slides along the movable adapter frame (3) to approach or move away from the measuring turntable (1).

2. The teaching aid for displaying line-surface relationships and measuring angles according to claim 1, characterized in that: The movable adapter frame (3) comprises a first rod body (31) rotatably connected to the measuring turntable (1); two second rod bodies (32) are rotatably connected to the first rod body (31); the two second rod bodies (32) are arranged in parallel; a third rod body (33) is rotatably connected between the two second rod bodies (32); the third rod body (33) is parallel to the first rod body (31).

3. The teaching aid for displaying line-surface relationships and measuring angles according to claim 2, characterized in that: The fixing seat (2) comprises a fixing rod (21) rotatably connected to the measuring turntable (1), a plurality of elastic buckles (22) are arranged at intervals on the fixing rod (21), and a mounting bayonet (221) is arranged on the elastic buckle (22), and the mounting bayonet (221) is arranged in a direction away from the measuring turntable (1) and is used for being clamped on a side to be measured of the model to be measured.

4. The teaching aid for displaying line-surface relationships and preliminary angle measurement according to claim 3, characterized in that: The indicating rod (4) comprises a fourth rod (41) parallel to the first rod (31), the fourth rod (41) being connected to two sliding blocks (42), the sliding blocks (42) being slidably mounted on the second rod (32) and corresponding one to one with the second rod (32).

5. The teaching aid for displaying line-surface relationships and preliminary angle measurement according to claim 4, characterized in that: The measuring turntable (1) comprises a first disk body (11) and a second disk body (12); the first disk body (11) and the second disk body (12) are both semicircular structures; the first disk body (11) and the second disk body (12) are coaxially arranged; the first disk body (11) abuts against the first rod body (31); the second disk body (12) is arranged on a side of the first disk body (11) away from the first rod body (31); the first disk body (11) and the second disk body (12) are both rotatably connected with a rotating shaft (13); one end of the rotating shaft (13) is provided with a locking protrusion (14), and the other end passes through the first rod body (31), the first disk body (11) and the second disk body (12) in sequence to be connected to the fixing rod (21).

6. The teaching aid for displaying line-surface relationships and preliminary angle measurement according to claim 4, characterized in that: The first rod body (31) and the two second rod bodies (32), the third rod body (33) and the two second rod bodies (32), and the fourth rod body (41) and the two sliding blocks (42) are all rotatably connected via fasteners (43).

7. The teaching aid for displaying line-surface relationships and preliminary angle measurement according to claim 6, characterized in that: The fastener (43) connected between the fourth rod (41) and the two sliding blocks (42) is detachably connected with an elastic connecting rope (5), and the two elastic connecting ropes (5) cooperate with the fourth rod (41) to determine the three vertices of the angle.

8. The teaching aid for demonstrating line-surface relationships and measuring angles according to claim 6, characterized in that: The first rod body (31), the third rod body (33) and the fourth rod body (41) are provided with a plurality of mounting holes at equal intervals, and the plurality of mounting holes are used for the passage of the fasteners (43); the two second rod bodies (32) are provided with a plurality of fixing holes (321) at equal intervals, and the sliding block (42) is provided with a fastening hole, and the plurality of fixing holes (321) and the fastening hole are used for fixedly connecting the fasteners (43).

9. The teaching aid for demonstrating line-surface relationships and measuring angles according to claim 5, characterized in that: A first locking member (15) and a second locking member (16) are sleeved on the rotating shaft (13); the first locking member (15) is arranged between the locking protrusion (14) and the first rod body (31) for fixing the position of the first rod body (31); the second locking member (16) is arranged between the second disk body (12) and the fixing rod (21) for fixing the position of the second disk body (12); the first locking member (15) and the second locking member (16) are both threadedly connected to the rotating shaft (13).

10. The teaching aid for displaying line-surface relationships and preliminary angle measurement according to any one of claims 3 to 9, characterized in that: The fixing rod (21) is a long strip structure, and a plurality of elastic buckles (22) are arranged at intervals along the length direction of the fixing rod (21).

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